The invention pertains to a heat exchanger that extracts heat from an exhaust duct of a rocket engine to heat another fluid, particularly a propellant such as liquid oxygen (LOX).
For example, the well-known J-2 is a pump-fed liquid rocket engine having a heat exchanger in the turbine drive gas circuit for heating liquid oxygen. The heated oxygen is used in autogenous pressurization of the vehicle liquid oxygen tank. This engine is described in various publications including the “FINAL REPORT, DEVELOPMENT HISTORY OF THE 200,000- AND 225,000-POUND-THRUST J-2 ROCKET ENGINES” prepared by Rocketdyne Engineering of Canoga Park, Calif., in accordance with contract NAS8-19, Exhibit D, paragraph B.2.b of Modification 12b, dated 13 Dec. 1966, which is expressly incorporated by reference herein. Heat exchangers for oxidizer tank pressurization are described at pages 403-407 of the report. Also submitted in the Information Disclosure Statement filed herewith and expressly incorporated by reference herein are drawings from the J-2 Data Package published by Rocketdyne, sheets 1-114. The schematic of the exhaust system (sheet 94 of the data package) and the heat exchanger (sheet 100) are incorporated in the drawings of this application.